1. Field of the Invention
This invention relates to an apparatus for feeding and wrapping products and, in particular, to an apparatus capable of receiving, transferring and wrapping articles of delicate nature, such as confectionary products, from a packaging machine.
2. Description of the Prior Art
As is well known, confectionary products, such as chocolates, tablets of chocolate and the like, are often delivered by a packaging machine in a disorganized manner or, in any event, at different rate than the rate at which the products can be accommodated by a wrapping machine.
This gives rise to problems of synchronization between two machines. Attempts have been made to solve such problems. A horizontal belt conveyor has been used to forward products to the inlet of the wrapping machine where a fixed or movable stop element causes the products to pile up in columns. From there, a device is used to transfer the products one at a time and at a suitable rate to the wrapping machine.
Such a system has various drawbacks. The most serious drawback results from the fact the products, by piling up in a large number against the stop element, transmit pressure on one another as each product is added to a column. This pressure, which is greatest on the products adjacent the stop element, may damage the products to the extent of requiring the elimination thereof. Moreover, the friction caused by the movable belt rubbing the base of the products stacked against the stop element, results in heating and wearing out of the product and, particularly, where the products are chocolate, causes soiling of the belt.
In British Patent No. 1,268,573, which is owned by the assignee of this invention, an apparatus is disclosed which eliminates some of the above disadvantages. In such an apparatus, the products are conveyed to a stop element, similar to that mentioned above, by two belt conveyors arranged in series. The belt conveyor which is closest to the stop element, is faster than the other belt conveyor and has two optical sensors for detecting the presence of products at an intermediate zone and at the rearward end, respectively, of that belt conveyor.
The sensors, which dictate modifications of the speed of the wrapping machine between two different speeds as the length of the column of products stacked against the stop element varies, are capable of maintaining the column length within two predetermined values. However, such an apparatus has certain disadvantages. Namely, the frequent accelerations and decelerations of the wrapping machine cause higher stress and wear of mechanical members of the machine, particularly cams, shafts and parts subjected to sliding friction.
Further, the frequent accelerations and decelerations involve a larger consumption of electric energy, namely, at every deceleration of the wrapping machine some amount of the kinetic energy of the machine is dissipated, while during acceleration current absorption is much greater than the operating current.